All projects are always shown in the Navigator. There is no possibility to finish a project and/or to hide it in the common list. You can export the project into a separate file (Use main menu — Database — Export Project) and delete it from LeaderTask. You can imprort the project back into LeaderTask when you need it. You can unite a row of projects making them subprojects to one project and this way you will be able you collapse these projects in the Navigator. To make a project a subproject, click at the project and use the Ctrl+Arrow right hot key combination.